Turbo-machines



May 1, 1962 J. SZYDLOWSKI 3,032,313

TURBOMACHINES Filed April 1, 1957 2 Sheets-Sheet 1 May 1, 1962 J.SZYDLOWSKI 3,032,313

TURBO-MACHINES Filed April 1, 1957 2 Sheets-Sheet 2 I l a l 7 24 v .8 5.25 1 I I :1 -u

United States Patent ()fitice 3,032,313 Patented May 1, 1962 3,032,313TURBO-MACHINES Joseph Szydlowski, Bordes, France, assignor to SocieteBertin & Cie, Paris, France, a corporation of France Filed Apr. 1, 1957,Ser. N0. 649,666 Claims priority, application France Apr. 9, 1956 3Claims. (Cl. 253-39) In piping systems or conduits traversed by fluids,it has already been proposed to form a divergent portion of such apiping system or such a conduit by a fluid layer generated by theexpansion of an auxiliary fluid under pressure, in a nozzle in the formof a suitably-directed slot which is formed on the solid Wall, in thezone at which the divergence of the conduit is to begin.

The present invention relates to the application of such fluiddivergents to the channels of turbo-machines (such as compressors, pumpsor turbines) and has for its object to permit of the replacement, atleast in part, of the usual solid blades of these machines by orientedfluid layers.

In actual fact, the grids of blades of compressors or pumps andsometimes of turbines frequently comprise divergent sections of passage,especially on the stators or rotors of compressors and on the exhaustrectifiers. of turbines.

In all these cases, the solid blades or vanes of the usual type areadvantageously replaced in the present invention, by several series ofsuitably-directed fluid screens produced by means of nozzles in the formof slots oriented in the desired sense on truncated vanes distributedabout the rotation axis of a turbo machine and having an axial lengthless than the corresponding axial sections of the rotor or stator inwhich they are disposed. These slots form nozzles. The truncated vanesor b'ades are restricted to a leading portion of the vane and the fluiddischarged therefrom through said nozzles form extensions of the vaneseffective to eflect energy transfer with the main fluid stream flowingthrough the turbo machine supplied with auxiliary fluid under pressurefrom an appropriate source.

The auxiliary fluid may be of any kind, liquid or gaseous, as may alsothe principal fluid which passes through the turbo-machine. In general,there will be employed as the auxiliary fluid aderivation of the mainfluid taken at a point of its circuit at which it has a suflicientpressure, for example at a downstream stage in the case of a compressorwith a number of stages.

" .The auxiliary fluid, whatever its origin may be, may be pumped orcompressed by means of accessory apparatus adapted for that purpose.

The description which follows below with reference to the accompanyingdrawings (which are given by way of example only and not in any sense byway of limitation) will make it quite clear how the invention may becarried into effect, the special features which are brought out, eitherin the drawings or in the text, being understood to form a part of thesaid invention.

FIG. 1 is a developed view of the blades of the usual type or rotor andstator of an axial compressor;

FIG. 2 shows the use of fluid screens in replacement of the blades ofthe stator;

FIGS. 2a, 2b, and 2c are diagrams of speeds of How through the stator ofFIG. 2;

FIG. 3 is a diagrammatic view in elevation, showing a slot and itssupport;

FIG. 3A, is a vertical sectional view illustrative of an embodiment inwhich fluid is provided to rotary vanes of a rotor;

FIG. 4 shows an alternative form in which both the driving blades andthe guiding blades of the compressor are constituted by fluid screens;and

FIG. 5 is a diagrammatic view illustrative of the application of theinvention to a diffuser of a centrifugal compressor.

The developed view of FIG. 1 shows a typical example of a stage of anaxial compressor with its driving blades M and its fixed guiding bladesD which are both formed of solid profiled vanes 1 and 2. This assemblymay be repeated along the circuit of the active fluid to be compressedin the case of compressors having a number of stages. The active fluidcirculates from left to right; it passes into the rotor M, the directionof rotation of which is indicated by the arrow 1'' and passes out of thestator D.

In the form of embodiment of the invention shown in FIG. 2, the rearportion of the solid guiding blades 2 which define divergent channels,is replaced by fluid screens 3. In th s case, FIG. 3, the solid elementsof the guiding blades D are hollow members or truncated vanes reduced tothe front portion 4 of the blades. These portions are hollow and have asubstantially flat high pressure side and an arcuate low pressure sideand each have a tapered leading edge and a blunt downstream edgeportion. They act as supply collectors for nozzles 5 dis-. posed closelyadjacent the blunt edge on the downstream edge portion. The nozzles areformed by radially elongated openings having the form of narrow slotshaving a radial length approximately the height of each element 4. Theseslots open to the high pressure side and are suitably directed in orderthat the fluid which is discharged through them can produce the fluidscreens de-. sired. Pressure fluid is supplied internally of the bladesthrough a radial opening 6 in the housing 11, in com munication with amanifold 12 connected to a conduit 12 through which the fluid issupplied either from a separate source or from the main fluid.

When the flow is considered at the outlet of the blades 1 of the rotor,this possesses components of speed similar to those which are shown inFIG. 2a, in which V is the absolute speed. V is the tangential componentand V is the axial component.

The supports 4 of the slots 5, by reason of their shape similar to thefront portions or leading portions of blades, modify slightly thetriangle of speeds (see FIG. 2b); the tangential component V becomes Vwhich is smaller, the axial component V becomes V which is slightlygreater, whilst the absolute speed V becomes V which is smaller as aresult of the increase of the sections which may be due either to thechange in the mean angle tangential component mV (see FIG. 2c) where 'm'and m are the output-masses respectively of the whole of the fluidscreens and the principal flow.

In order to cancel this tangential component mV then mV should besubstantially equal to m'V' the direction of the speed V of injection ofthe auxiliary jets being in addition substantially tangential andopposite to the direction of rotation of the rotor f. This is broughtout in FIG. 20, in which the lengths of the vectors represent themomentums mV 111V; and mV and are proportional to the lengths of thecorresponding vectors of FIG. 2b; from which the resultant is mV Thefinal resultant mV is smaller than mV by reason of the increase inpressure, but it has the same direction as this latter.

The invention also provides for applying fluid to the blades or vanesthat are capable of rotating. Thus, in FIG. 3A is illustrated anembodiment of the invention in which hollow rotary vanes 4 are connectedto a hollow shaft 7 by means of hollow support means 8. These blades areprovided with nozzles 5 disposed on the vanes as heretofore describedwith respect to FIG. 3.

Internal fluid is applied to the interior of the blades through thehollow shaft 7- having radial openings communicating with a channel 9 onthe supporting means 8. Fluid enters the vanes through openings 10..

FIG. 4 shows an arrangement similar to that of FIG. 2, but in this casefluid screens 3 are utilised both for the rotor and for the stator. Thedriving blades are constituted by supports 4' provided with slots 5'which produce fluid screens 3 having a suitable direction. The supply ofthe slots 5 with auxiliary fluid may be eflected by taking advantage ofthe centrigugal forces set up, the fluid being admitted through orificeslocated in the vicinity of the axis of the rotor in the manner of theembodiment in FIG. 3A.

It should be noted in the case of a rotor with fluid blades of thiskind, that in consequence of the orientation of the slots 5' in thedirection of rotation 1, there is produced a reaction effect tending toact in opposition to the rotation of the rotor and giving rise for thatreason to extra work in order to effect that rotation; this increase indriving work shows itself in the principal flow by a work ofcompression.

FIG. 5 shows an assembly equivalent to that preceding,

in the case of a diffuser of a centrifugal compressor, the rotor ofwhich is shown at R. The fixed blades are constituted by supports 4"provided with slots 5" directed. at an angle a, with the radius in adirection substantially tangential and opposite to the direction ofrotation f.

It will of course be understood that modifications may be made to theforms of embodiment which have just been described, in particular by thesubstitution of equivalent technical means, without thereby departingfrom the scope of the present addition.

What is claimed is:

1. A turbo machine of the axial flow type having cooperative rotor andstator sections in energy transfer relation with a main fluid streamflowing therethrough, at least one of said sections comprising aplurality of angularly spaced hollow members distributed about therotation axis of said axial flow type turbo machine and c nstructed' inthe form of radially extending truncated hollow vanes restricted to aleading portion, each vane having a substantially flat high pressureside and an arcuate substantially convex low pressure side and eachhaving a tapered leading edge and a blunt downstream edge portion, eachtruncated hollow vane having an axial length substantially less than theaxial length of said section in which the vanes are disposed, each ofsaid hollow vanes having a narrow, radially elongated opening forming anozzle closely adjacent said blunt edge on said downstream edge portionand disposed opening to said high pressure side, means for supplyinginternally of said vanes pressure fluid discharged in operation out ofthe respective nozzles of said hollow vanes as jet-streams to formindividual sheet-like streams of pressure fluid, and each nozzle havinga radial length and a width dimension selected to cause said streams tocorrespond to fluid extensions of the respective hollow vanes to formfor each hollow vane a trailing portion and each disposed to cause saidpressure fluid to issue in operation into said main fluid stream andthereby in conjunction with a given respective leading portion act as acomplete vane in transferring energy.

2. A turbo machine of the axial flow type having cooperative rotor andstator sections in energy transfer relation with a main fluid streamflowing therethrough, at least one of said sections comprising aplurality of angularly spaced hollow members distributed about therotation axis of said axial flow type turbo machine and constructed inthe form of radially extending truncated hollow vanes restricted to aleading portion, each vane having a substantially flat high pressureside and an arcuate substantially convex low pressure side and eachhaving a tapered leading edge and a blunt downstream edge portion, eachtruncated hollow vane having an axial length substantially less than theaxial length of said section in which the vanes are disposed, each ofsaid hollow vanes having a narrow, radially elongated opening forming anozzle closely adjacent said blunt edge on said downstream edge portionand disposed opening to said high pressure side, means for supplyinginternally of said vanes pressure fluid discharged in operation out ofthe respective nozzles of said hollow vanes as jet-streams to formindividual sheet-like streams of pressure fluid, and each nozzle havinga radial length and a width dimension selected to cause said streams tocorrespond to fluid extensions of the respective hollow vanes to formfor each hollow vane a trailing portion and each disposed to cause saidpressure fluid to issue in operation into said main fluid stream andthereby in conjunction with a given respective leading portion act as acomplete vane in trans-' ferring energy, and said nozzles being disposedfor discharging said sheet-like jet-streams in a direction creating areaction efiect tending to oppose rotation of said rotor.

3. A turb'o machine of the axial flow type having cooperative rotor andstator sections in energy transfer relation with a main fluid streamflowing therethrough, a

section on said rotor and a next axially adjacent section on said statoreach comprising a plurality of angularly spaced hollow membersdistributed about the rotation axis of said axial flow type turbomachine rotor and constructed in the form of radially extendingtruncated hollow vanes restricted to a leading portion, each vane havinga substantially flat high pressure side and an arcuate substantiallyconvex low pressure side and each having a tapered leading edge and ablunt downstream edge portion, each truncated hollow vane having anaxial length substantially less than the axial length of said section inwhich the vanes are disposed, each of said 'hollow vanes having anarrow, radially elongated opening forming a nozzle closely adjacentsaid blunt edge on said downstream edge portion and disposed opening tosaid high pressure side, means for supplying internally of said vanespressure fluid discharged in operation out of the respective nozzles ofsaid hollow vanes as jet-streams to form individual sheet-like streamsof pressure fluid,

and each nozzle having a radial length and a width dimension selected tocause said streams to correspond to fluid extensions of the respectivehollow vanes to form for each hollow vane a trailing portion and eachdisposed to cause said pressure fluid to issue in operation into saidmain fluid stream and thereby in conjunction with a given respectiveleading portion act as a complete vane in trans"- ferring energy.

References Cited in the file of this patent UNITED STATES PATENTS2,344,835 Stalker Mar. 21, 1944 2,408,788 Ludington et a1. Oct. 8, 1946-2,630,965 Greatrex et a1 Mar. 10, 1953 2,763,427 Lindsey Sept. 18, 19562,825,532 Kadosh et al. Mar. 4, 1958 2,830,754 Stalker Apr. 15, 19582,935,245 McDonald May 3, 1960 2,944,729 Foley July 12, 1960 FOREIGNPATENTS 586,010 Germany Oct. 14, 1933 has.

